Application of Motion Control Technology in Fiber Laser Cutting

The DM series CNC laser cutting machine is a gantry moving form, and it is bilaterally driven and driven, that is, rack and pinion and servo motors are symmetrically installed on both sides of the gantry beam to realize double-pinion-rack transmission and double-servo motor drive. The double-sided drive ensures the balance of the force on the crossbeam and the synchronization of the crossbeam operation.　　 The synchronicity of the bilateral drive affects the speed, acceleration, positioning accuracy and stability of the gantry beam. The bilateral drive servo motors of DF series CNC fiber laser cutting machine are equipped with encoders to realize speed and position control. Both sides of the servo motors have precise zero positions, and after returning to the reference point at the same time, the double zero position is taken as the starting point of synchronization, and the accuracy is higher. The double servo motors complete the synchronous control of speed and position within the position control cycle. There is no master-slave distinction, and it is completely synchronous and non-differentiated control. When the gantry axis moves in a large stroke, the mechanical error of the bilateral transmission is difficult to avoid. The unique synchronous control technology of the DF series CNC system can compensate the positions of the two sides of the synchronous control respectively, eliminate the mechanical error of the bilateral transmission, and ensure the positioning accuracy of the gantry axis in the full range.　　F-axis technology 　　The role of the F-axis: the control of the focusing lens. According to the focus position set by the expert database, the motor drives the focus lens to move.　　 F-axis optical path compensation technology: the automatic focusing cutting head is more accurate, and it can be used as optical path compensation.　　Equal optical path technology Definition of 　　equal optical path: 　　The path length of the laser from the laser exit, through the external optical path and each mirror to reach the cutting head is called the optical path. Due to the divergence angle of the laser beam, the focusing effect and beam diameter of different optical paths are different; the control technology can keep the optical path constant when the cutting head moves. The method to achieve equal optical path: the compensation mechanism drive and the laser cutting head drive share a transmission pair on the beam; the movement direction of the compensation mirror mechanism is consistent with the movement direction of the laser cutting head and starts and stops at the same time. The compensation mirror mechanism is on the beam The ratio between the moving speed V1 on the linear guide pair and the moving speed V2 of the laser cutting head on the beam linear guide pair is: V1:V2u003d1:2. When the laser cutting head moves along the Y axis for a distance of 2Y, the compensation mirror moving distance is Y to ensure a constant optical path length.　Power control technology 　　Corner power ramp adjustment: The machine tool will inevitably decelerate when cornering, and the laser power can be automatically adjusted according to the actual movement speed of the cutting head. Real-time performance is better.　　The climbing control of the welding power during arc starting and ending, to improve welding quality and appearance. The power ramp time is controllable.　　Expert database technology 　　Expert database understanding: 　　In control technology, the use of a database can be understood as a collection of many data tables, and the CNC system calls the content of one of the data tables to set various parameters. Such as: movement speed, power control output voltage, punching time (pause time) and so on.　　The method to realize the expert database: 　　The product provides an interface of the expert database, which can set parameters, modify parameters, create new materials and other user operations. The operated value is saved as a database file, and the storage location is on the CF card. The start position of the part program is indexed to a table in the database file by keywords, and then the content of the data table is called. Surface following technology The basic principle of surface following technology The sensor on the cutting head senses the height of the steel plate (capacitance or inductance) and feeds it back to the control system. The control system directly uses the feedback to control the Z-axis motor, or after processing by the numerical control system, the numerical control system controls the Z The shaft motor achieves the effect that the distance between the cutting head and the plate remains basically unchanged.